Conceptual Questions

For Questions 1, 2, and 3 interpret the position graph given in each figure by writing a very short “story” of what is happening. Be creative! Have characters and situations! Simply saying that “a car moves 100 meters to the right” doesn’t qualify as a story. Your stories should make specific reference to information you obtain from the graph, such as distance moved or time elapsed.

FIGURE Q2.1

FIGURE Q2.1 Full Alternative Text
FIGURE Q2.2

FIGURE Q2.2 Full Alternative Text
FIGURE Q2.3

FIGURE Q2.3 Full Alternative Text
FIGURE Q2.4 shows a position-versus-time graph for the motion of objects A and B as they move along the same axis.
1. At the instant $t = 1 s,$ is the speed of A greater than, less than, or equal to the speed of B? Explain.
2. Do objects A and B ever have the same speed? If so, at what time or times? Explain.
FIGURE Q2.4

FIGURE Q2.4 Full Alternative Text
FIGURE Q2.5 shows a position-versus-time graph for the motion of objects A and B as they move along the same axis.
1. At the instant $t = 1 s,$ is the speed of A greater than, less than, or equal to the speed of B? Explain.
2. Do objects A and B ever have the same speed? If so, at what time or times? Explain.
FIGURE Q2.5

FIGURE Q2.5 Full Alternative Text
FIGURE Q2.6 shows the position-versus-time graph for a moving object. At which numbered point or points:
1. Is the object moving the slowest?
2. Is the object moving the fastest?
3. Is the object at rest?
4. Is the object moving to the left?
FIGURE Q2.6

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FIGURE Q2.7 shows the position-versus-time graph for a moving object. At which numbered point or points:
1. Is the object moving the fastest?
2. Is the object moving to the left?
3. Is the object speeding up?
4. Is the object turning around?
FIGURE Q2.7

FIGURE Q2.7 Full Alternative Text
FIGURE Q2.8 shows six frames from the motion diagrams of two moving cars, A and B.
1. Do the two cars ever have the same position at one instant of time? If so, in which frame number (or numbers)?
2. Do the two cars ever have the same velocity at one instant of time? If so, between which two frames?
FIGURE Q2.8

FIGURE Q2.8 Full Alternative Text
You’re driving along the highway at a steady speed of 60 mph when another driver decides to pass you. At the moment when the front of his car is exactly even with the front of your car, and you turn your head to smile at him, do the two cars have equal velocities? Explain.
A bicycle is traveling east. Can its acceleration vector ever point west? Explain.
(a) Give an example of a vertical motion with a positive velocity and a negative acceleration. (b) Give an example of a vertical motion with a negative velocity and a negative acceleration.
A ball is thrown straight up into the air. At each of the following instants, is the magnitude of the ball’s acceleration greater than $g$ , equal to $g$ , less than $g$ , or 0? Explain.
1. Just after leaving your hand.
2. At the very top (maximum height).
3. Just before hitting the ground.
A rock is thrown (not dropped) straight down from a bridge into the river below. At each of the following instants, is the magnitude of the rock’s acceleration greater than $g$ , equal to $g$ , less than $g$ , or 0? Explain.
1. Immediately after being released.
2. Just before hitting the water.
FIGURE Q2.14 shows the velocity-versus-time graph for a moving object. At which numbered point or points:
1. Is the object speeding up?
2. Is the object slowing down?
3. Is the object moving to the left?
4. Is the object moving to the right?
FIGURE Q2.14

FIGURE Q2.14 Full Alternative Text